Synthetic drying oils



April 27 1948- H. s. BLOCH I 2,440,459

SYNTHETIC DRYING OILS 4 med April. 2.a, 1944 I r'qcar azz OP :ying foci .fled efbrrnzn 5 ,-.epamt'con l U a f' 5 v I Zone yvcocagane, s

roca rorfrs om lucfge Patented Apr. 27, 1948 l ASYNH'HITIC DBYING OILS Berman S. Bloch, Riverside, Ill., assignor to Univernal Oil Producti Company, Chicago, Ill., a

corporation ol' Delaware Application April 28, 1944, Serial No. 533,258

A 9 Claims. (Cl. 196-78) This is a continuation-in-partoi my copendand 'a catalyst phase, and recovering the drying oil from the catalyst phase.

A further object of my invention comprises an improvement in the manufacture of a material having the properties of a drying oil suitable for use in varnishes, paints and other protective and decorative coatings by treating the used catalyst phase which is separated i'rom a hydrocarbon conversion process eiiected inthe presence of a catalyst capable of causing conjunct polymerization of oleilns such as hydrogen -iluoride, sulfuric acid, aluminum chloride with or without hydrogen chloride or organic chlorides, and the like.

Broadly my invention comprises reacting a hydrocarbon charging stock in the presencev o! a catalyst, separating the reaction material into a hydrocarbon phase and a catalyst phase. removing high boiling relatively saturated hydrocarbons from the catalyst phase and recovering from the treated catalyst phase an oil having the proporties of a drying oil.

When hydrocarbon conversion reactions are carried out inthe presence of a catalyst such as aluminum chloride, hydrogen fluoride, sulfuric acid and the 1ike,rthe used catalyst phase contains certain valuable organic compounds associated with the catalyst. presumably in the form of a catalyst-hydrocarbon complex. It is this organic material which can be recovered from the used catalyst phase by .decomposing said complex which is referred to in the present specication and claims as organic diluent.

In preparing synthetic drying oils from a catalyst hydrocarbon complex formed during the catalytic conversion of hydrocarbons, I have found that the organic diluent of the catalyst.

complex often dries to a illm which is permanently sticky and tacky rather than to one which is hard and firm to the touch, as is required in coating compositions. that if the catalyst complex is treated to remove relatively saturated material `(having a boiling point up to about 371 C.) which is entrained I have now discovered or dissolved in the catalyst phase and which is not separable from the drying oil after decomposition of the catalyst complex, the resulting dryv ing oil product has greatly improved drying properties and sets to a ilrm hard illm. Unless this higher boiling saturated material is removed,.it

acts as a tackier in the dried illm as it is too high boiling to evaporate from the drying oil.

In one embodiment the present invention relates to an improvement in a process for the preparation of a drying oil by reacting a hydrocarbon charging stock in the presence of a cat alyst, introducing the reaction mixture Vinto a settling zone and therein separating an upper hydrocarbon layer from a lower catalyst layer containing organic diluent, separating catalyst from the catalyst layer and recovering the organic diluent. said improvement comprising subjecting the catalyst phase to extraction with a suitable solvent to remove high boiling relatively saturated compounds prior to decomposition of said catalyst phase.

I'he present invention is particularly benecial in the treatment oi' the catalyst phase recovered from processes wherein the charging stock comprises oleflnic hydrocarbons. It is less applicable in the preparation oi drying oils in which low boiling saturated hydrocarbons comprise a major portion of the charging stock since in these processes the catalyst phase undergoes continuous extraction with evaporatable hydrocarbons and the concentration oi high boiling saturated hydrocarbons in the hydrocarbon phase, from which they may be dissolved by the catalyst phase, is low.

In addition to processes in which a catalyst complex is specifically prepared for the purpose oi.' manufacturing drying'oils, the desired organic diluent mayvalso be secured from the catalyst phase formed in processes such as the alkylation of isoparaillns with oleiins, the isomerization o hydrocarbons, cracking. etc.

The material which may be employed to re-I move the undesirable high boiling saturated compounds from the catalyst phase includes any relatively low boiling nonreactive hydrocarbon such as propane, butanes, pentane, petroleum ether, aromatic hydrocarbons such as toluene or benzene, etc. Any solvent which is inert toward the hydrocarbon-catalyst complex, which is sumciently volatile to evaporate from illms oi' paints or varnishes, and which is substantially immiscible with the catalyst-hydrocarbon complex is suitable lor this purpose. Thus, ii the complex 'is'of such composition that the catalyst is incapable of extensive further reaction, low-boiling. olefin-containing extractants may be used, or ethers may be employed, suchas diethyl ether or dioxane. Such extractive materials should in general boil below about 200 C. or at most below about 250 C.the upper boiling rangeof evaporatable paint solvents or thinnerscommonly used. Petroleum distillate cutsv boiling within this range are quite suitable and may be conveniently employed for extractive purposes in this process.

A typical operation for the manufacture of a drying oil may be carried out according to the following-description in which the reacting materials comprise an olenic charging stock and a hydrogen fluoride catalyst.

A hydrocarbon charge containing normally gaseous and/or normally liquid oleilns is treated in the presence of hydrogen fluoride undersufflcient pressure to maintain the mixture in substantially liquid phase, said pressure usually being below about 500 pounds per square inch. Intimate contact between the hydrocarbons and catalyst may be maintained by some form of agitation, such as mixing, stirring, etc., so as to form a mixture or emulsion of hydrocarbon and hydrogen iluoride. A reaction temperature of from about 18 C. to about 149 C. and preferably from about to about 93 C. is usually employed. Upon completion of the reaction, the products are allowed to settle, and a hydrocarbon layer is separated from the catalyst layer.

The catalyst phase is then directed to a solvent treating zone wherein it is commingled with a low boiling non-reactive hydrocarbon solvent and thoroughly mixed. The mixture of catalyst phase and solvent is then allowed to stratify and the raiiinate, comprising the catalyst complex from which undesirable saturated material has been removed, is separated from an upper extract layer comprising the solvent and the saturated high boiling material.

From the solvent treating zone the catalyst phase, from which the undesirable, high boiling relatively saturated compounds have been removed, is directed to an acid-recovery zone wherein hydrogen uoride is separated by distillation, treatment with water and/or aqueous alkali or other suitable means. Most suitably it is recovered as, or reconverted to, anhydrous hydrogen uoride and recycled to the reaction zone.

The remaining material after removal of hydrogen fluoride may be treated in a number of ways to remove any free acid lei't and to obtain a purified drying oil. A simplemethod comprises either steam or vacuum distillation to recover an oil having the desired properties.

In an alternate method of operation, the puriiled organic diluent may be recovered by commingling the catalyst layer with water or with aqueous hydrogen iluoride of constant-boiling composition. The water serves to dissolve any f ree acid present, while the organic diluent rises to the top of the mixture and may be withdrawn. If desired, the uidity of the catalyst layer may be increased by commingling it with a non-reactive hydrocarbon. such as pentane, and after thorough mixing the solution is treated with a suitable alkaline reagent to neutralize any remaining free acid present. The treated mixture is then directed to a separation zone in which the hydrocarbon solvent is removed by suitable means, such as distillation, and the finished drying oil product recovered. The hydrocarbon solvent may be recycled for further use.

The drying oil product is a sweet-smelling material ranging in color from'light yellow to dark brown and on exposure to air dries to a solid film. It has an average molecular weight of from about 250 to about 500, although oils having molecular weights of as low as about to as high as about 1000 have been prepared, these oilsV comprising compounds of substantially the same homologous structure and chemical properties. These properties include average bromine numbers of about to about 200; average number of double bonds per molecule of more than 2 and less than 5; densities of about 0.85 to about 0.95; specific dispersions. of about to about 175 (but usually below about specic refractions of about 0.327 to about 0.335, and carbon to hydrogen ratios close to 1:1.65.

Similarly, if the organic diluent is to be recovered from a used catalyst phase resulting from the conversion of hydrocarbons in the presence of a catalyst comprising sulfuric acid or a metal halide such as aluminum chloride, the catalyst phase is separated from the upper `hydrocarbon layer as hereinbefore set forth. The catalyst phase is then directed to a solvent treating zone where it is subjected to extraction to remove the undesirable high boiling relatively saturated material. The extraction may be effected by bubbling in a light hydrocarbon such as petroleum ether through the mixture of acid nand hydrocarbons. The catalyst phase may then be sub- Jected to hydrolysis in the presence of any residual light hydrocarbon, reiluxing the material under conditions such that the temperature is maintained at a substantially constant level. The mixture is allowed to settle, suillcient alkaline reagent added to eiect neutralization of the mixture, the hydrocarbon layer separated from the aqueous layer and the low boiling hydrocarbons removed by distillation, followed by recovery of the drying oil product. By commingling an inert low boiling hydrocarbon with the hydrolyzing y medium, the exothermic heat of hydrolysis which is liberated is dissipated, thus preventing or diminishing undesirable polymerization reactions which may take place. bons which may be used include propane, butane, pentanes, or a mixture thereof.

' The process of the present invention will be further described in relation to the accompanying flow diagram which illustrates some of the specific embodiments of the present invention. Reierring to the diagram, a suitable hydrocarbon charging stock as hereinabove described, for example an olenic'polymer gasoline, is introduced through line i into sludge-forming zone 2 wherein it is contacted with a sludge-forming catalyst such as hydrogen i'luoride introducedinto zone 2 through line 3. The reactants are preferably stirred to obtain intimate contact between the hydrocarbon and catalyst reactants and are maintained within the reactor at a temperature of from about 18 to about 149 C. and preferably at aI superatmospherio pressure sufiicient to maintain the reactants in liquid phase, especially when hydrogen fluoride is employed as the sludge-forming catalyst. As the reaction proceeds, the reaction mixture is vigorously stirred in zone 2, forming an emulsion between the sludge, catalyst and hydrocarbons present Itherein which upon settling separates into two distinct phases, a lower layer containing substantially all of the hydrogen fluoride charged to the reaction in a combined form as the intermediate sludge reaction product and an upper hydrocarbon layer Low boiling hydrocarl containing predominantly saturated hydrocarbons as the other product of the sludge-forming reaction. In order to eect the separation of the two layers, the reaction product formed in zone 2 is withdrawn through line l into separation zone 5, wherein it is permitted to stand quiescent until separation of the above indicated phases has taken place. The upper layer. comprising chiefly saturated hydrocarbons, is withdrawn through line 6 and discharged from the process or otherwise treated to recover valuable hydrocarbon by-products therefrom. The lower sludge layer separating in zone i is withdrawn through with the` sludge previously charged into zone l.

The mixture of extractant and sludge is then conveyed from zone 8 through line I0 into separation zone il where the respective extract and raffinate (sludge) phases are allowed'to stratify into two distinct layers. The extract layer comprising the extractant and the saturated hydrocarbons removed from the sludge by the extraction step are decanted from the immiscible sludge layer and withdrawn from the process through line i2. When desired, the extractant may be recovered from the extract phase and segregated from the extracted saturated hydrocarbons, for example by fractional distillation, and recycled as fresh extractant to solvent treating zone 8.

The lower raillniate layer separated from the extractant in zone il is withdrawn through line i3 and charged into sludge decomposition zone i4 wherein the sludge is decomposed and the orl ganic diluent hydrocarbons recovered therefrom Zone i4 may be operated in accordance with any of the hereinabove specified means for decomposing the sludge intermediate product, the particular method selected depending largely upon the catalyst utilized into the sludge-forming zone. As hereinabove noted, such methods for decomposition of the sludge include aqueous hydrolysis by water alone or in solution with a suitable caustic, simple batch or vacuum distillation. or by other means known to the art. One of the preferred methods for decomposition of the sludge is by means of aqueous hydrolysis whereby the sludge is thoroughly mixed with water to decompose the catalyst-organic diluent bonds comprising the sludge. When the aqueous hydrolysis method is employed for decomposition of the sludge, the hydrolyzing medium (water, a dilute caustic, or an aqueous acid) is charged into zone i4 vla line i5 and intimately contacted with the sludge in zone il by a suitable stirring device. The aqueous phase containing the dissolved sludge-forming catalyst released from the sludge by the hydrolytic decomposition thereof i's removed from zone il by d ecantation from the organic diluent phase through line I and may be conveyed to a catalyst recovery plant not illustrated on the diagram, for reconcentrating the catalyst to a form suitable for utilization in the sludge-forming reaction where the-anhydrous or nearly anhydrous catalyst is required to form rthesludge. The upper layer separating from the .aqueous phase in zone il contains the organic diluent hydrocarbon product of the present process which is withdrawn from zone il through line." to storage or to a distillation unit where certain fractions may be separated therefrom,

for example by fractional distillation. Vhaving boiling points and other properties suitable for particular purposes.

The following example illustrates the improvements obtainable by the use of the present ininvention, but it is not intended to linut the in- Avention in accordance with the data submitted.

An organic diluent was obtained by the aqueous hydrolysis of a catalyst phase prepared by reacting polymer gasoline in the presence ofhydrogen fluoride. The catalyst phase was divided into two v inert toward and substantially immiscible with which in six days dried to a hard nlm (as corn-V pared with 'l to 9 days for alkali-refined linseed oil under the same conditions). The drying oils obtainedl from the untreated and treated catalyst phase were found to have the following physical properties:

Properties Untreated Treated Density amil...K v 0. 850 0. 864 Gardner Color l2 12 Bromine N umher. 181 l 198 Refractive Index Np l. 4846 l. 4875 S eciilc Disersion.. l 135 olecular eight 298 Molecular Formula CHg s CHs1 s Number of Double Bonds Per Molecule. l

The extracted material (which amounted to about 17 percent of the hydrocarbon content of the catalyst phase) was a mixture of relatively high-boiling saturated hydrocarbons with an initial boiling point of about C. and a bromine number of 4.

I claim as my invention:

1. A processifor the production of synthetic drying oils which comprises reacting an olenic hydrocarbon charging stock in the presence of a coniunct polymerization catalyst comprising hy'- drogen fluoride to form a catalyst-hydrocarbon complex, separating the resultant reaction products into a hydrocarbon phase and a catalyst phase comprising said complex and relatively saturated higher boiling compounds, extracting said catalyst phase with a substantially non-reactive solvent boiling below aboutA 250 C. under conditions to\remove said relatively saturated higher boiling compounds without effecting conversion of said solvent, said solvent being substantially said complex, and separating from the thus extracted catalyst phase a hydrocarbon drying oil substantially free of said compounds.

2; 'I'he process of claixni wherein said solvent lcomprises a hydrocarbon solvent.

3. The process of claim 1 wherein said solvent comprises a petroleum distillate.

comprises pentane.

5. The process ofclaim 1 wherein said charg-V 'I ing stock comprises a polymer gasoline.

6. A process for the production of .synthetic drying oils which comprises reacting, an olenic hydrocarbon fraction in the presence of hydrogen fluoride at a temperature of from about 10 C. to about 93 C. and at a pressure sufficient to maintain the mixture in substantially the liquid phase, allowing the reaction mixture to settle and separating an upper hydrocarbon layer from a lower hydrogen uoride layer comprising a hydrogen uoride-hydrocarbon complex, and relatively saturated higher boiling compounds, extracting said hydrogen uoride layer with a non-reactive hydrocarbon solvent boiling below 250 C. under conditionsto remove said relatively saturated higher boiling compounds without effecting conversion of said solvent, and separating from the thus extracted hydrogen uoride layer a hydrocarbon drying oil substantially free of saidcompounds.

7. The process of claim 6 wherein said hydrocarbon drying oil is separated from the extracted hydrogenv uoride layer by distillation.

5 drogen uoride.

9. The process of claim 6 wherein said solvent comprises pentane.

HERMAN S. BLOCH.

10 REFERENCES CITED The following references are oi record in the ille of this patent:

UNITED STATES PATENTS 15 Number Name Date 38,640 Millochau May 19, 1863 190,762 Jenney May 15, 1877 1,211,721 Landsberg Jan. 9, 1917 2,217,919 Rostler et al. Oct. 15, 1940 2o 2,302,956 Retailliau Nov. 24, 1942 2,354,554 Showalter et al July 25, 1944 2,371,341 Matuszak Mar. 13, 1945 2,371,652 Rostler et al Mar. 20, 1945 2,384,735' Frey I Sept. 11, 1945 25 2,404,483

- 8. The process of claim 6 further characterized in that said extracted hydrogen uoride layer is subjected to hydrolysis and said hydrocarbon drying oil isseparated from the resultant aqueous hy- Frey 1I July 23, 1946 

